Clay digger



May 29, 1951 H. AJGILLERSTROM 2,554,568

CLAY DIGGER Filed July 17, 1946 2 Sheets-Sheet 1 pgs,

INVMTOR. H/LMER A. G/LLERST/POM A TTORNE Y May 29, 1951 H. A. GILLERSTROM 2,554,568

CLAY DIGGER Filed July 17, 194e 2 Sheets-Sheet 2 y INVENTOR. ,f1/MER A. G/LLERST/POM ATTORNEY Patented May 29, 1951 CLAY BIGGER Hilmer A. Gillerstrom, Aurora, Ill., assignor to Independent Pneumatic Tool Co., Chicago, Ill., a corporation of Delaware Application July 17, 1946, Serial No. 684,303

Claims. (Cl. 121-40) My invention relates to a clay digger, more particularly of the pneumatically operated type and the objects of my invention are:

First, to provide a clay digger of this class in which the front head of the steel retainer assembly may be forced into clay or sand without dan-- ger of the accumulation of foreign matter about the hammer end of the piston adjacent the tool shank;

Second, to provide a clay digger of this class having passages in the side wall of the cylinder thereof, communicating with the breather port in the cylinder at the hammer end of the piston whereby exhaust air from the cylinder is directed into one of said passages causing air to fiow into the cylinder bore at the hammer end of the piston which air is exhausted therefrom by aspiration of the air through a separate passage means spaced from the exhaust port of the cylinder causing foreign matter to be carried outwardly of the cylinder bore at the hammer end of the piston therein;

Third, to provide a clay digger of this class having passage means from the cylinder exhaust port to the cylinder bore portion at the hammer end of the piston for conducting exhaust air into the cylinder bore at the hammer end of the piston for cooling the front head assembly of my clay digger;

Fourth, to provide a clay digger of this class having rubber cushion bumpers which eifectively dampen vibration of the rapidly reciprocating clay spade collar in the front head of my clay digger;

Fifth, to provide a clay digger of this class having rearwardly extended passage means comf municating with the relief port in the cylinder bore portion at the hammer end of the piston which permits the air to ebb and ow at the forward end of the piston whereby said relief port is protected from the entrance of foreign matter therein about the hammer end of the piston;

Sixth, to provide a clay digger of this class which cleans the cylinder bore portion at the hammer end of the piston with each stroke thereof; and

Seventh, to provide a clay digger of this class which is very simple and economical of construction, eicient in operation and which will not readily deteriorate or get out of order.

With these and other objects in view as will appear hereinafter, my invention consists of certain novel features of construction, combination and arrangement of parts and portions, as will be hereinafter described in detail and particularly set forth in the appended claims, reference being had to the accompanying drawings and to the characters of reference thereon forming a part of this application, in which: Y

Figure 1 is a fragmentary side elevational view of my clay digger showing portions broken away and in section to amplify the illustration; Fig. 2 is a fragmentary sectional view taken from the line 2-2 of Fig. l, showing parts and portions in elevation to facilitate the illustration; Fig. 3 is a transverse sectional View taken from the line 3 3 of Fig. 2; Fig. 4 is a transverse sectional View taken from the line 4 4 of Fig. 2; and Fig. 5 is atransverse sectional View taken from the line 5-5 of Fig. 2.

Similar characters of reference refer to similar parts and portions throughout the several views of the drawing.

The cylinder l, front head 2, piston hammer 3, chuck bushing 4, spade 5, shank bushing 6, cushion members l and 8, steel retainer bolt 9, and the cushion engaging collar l constitute the principal parts and portions of my clay digger.

The cylinder I is a substantially conventional air hammer cylinder having a substantially conventional reciprocating piston hammer 3 therein, as shown best in Fig. 2 of the drawings. It will be here noted, however, that the cylinder I is provided with rearwardly extending hollow passage portions la and ib communicating with relief ports lc and id respectively in the side wall of the cylinder bore portion le, at the hammer end portion 3a of the piston hammer 3. The conventional relief port is located in a similar position to the relief ports Ic and ld but is open directly externally of the cylinder l at substantially the location of the relief ports lc and id. The rearwardly extending hollow passage portions la and Ib are provided with open end portions If and lg outwardly of the cylinder exhaust opening I h, as shown best in Figs. 1 and 2 of the drawings. The exhaust opening i h is directed outwardly and forwardly toward the open end portions If and lg of the hollow passage portions l a and lb, as shown by arrows in Fig. 2 of the drawings. As shown in Fig. 1 of the drawings, the open end portion I g of the hollow passage portion I b is nearer to the exhaust opening Ih than is the open end portion if of the hollow passage portion la..

The chuck bushing 4 is arranged to surround the substantially square in cross section shank 5b of the spade 5 and is supported in an enlarged bore portion I 1c adjacent the bore portion I e of the cylinder I. The cushion engaging collar l0 2 is the shank bushing arranged to guide the.

shank of the spade 5 in reciprocative movement relatively thereto, as shown best in Fig. 2 ofthe drawings. The steel retainer bolt 9 is positioned in a boss portion 2a of the front head2 anden?. gages an arcuate portion im in the side wall of:

the cylinder l, securing the front head E on the cylinder I in substantially the conventional manner.

The operation of my clay digger is substantially as follows: 'When the blade 5c of the spades-5 is forced into clay or sand, the reciprocating piston ham,- mer 3, hammers the inner end of the shank 5b of the spade 5 forcing the same into said clay or sand. W ith continued movement of the spade 5, the front head Z of my clay digger is often forced into the clay or sand whereupon foreign matter tends to work through the chuck. The relief ports Ic and ld at the hammer end of the piston 3-in the side wall of the bore portion ie of the cylinder l, are covered by the backwardly extending hollow passage portions la and lb, whereby foreign matter is prevented from entering the relieffports c and id during operation of my clay digger when the front head thereof is immersed in the earth. With each stroke ofthe piston 3, air is exhausted through the angularly disposed port lh and the air emerging from the port Ih expands very rapidly in a cone-shaped fashion causing considerable Apressure at the'open end lg of the hollow passage portion ib, causing a forced draft through the hollow passage Ib and into the bore portion le at the hammer end of the piston 3. Simultaneously the exhaust air emerging from the port lh passes over the open end I f of the hollow passage portion ia aspirating the air from the hollow passage portion la which tends to exhaust foreign particles from the bore portionl le atthe hammer end 3a of the piston hammer 3. It will be here noted that the open end portion Ig of the hollow. passage portion Il)` is sufficiently close to the exhaust port lh to cause pressure therein to be exerted by rapid expansion of the air being exhausted from the port ih. The open end if of the hollow passage la, however, is slightly spaced from the port lh whereby the draftcreated by exhausted air from the port lh causesV aspiration of the air from the hollow pas-A sage portion la. The circulation of air through Ythe bore portion I e, at the hammer end 3a of the piston hammer 3, by means of the hollow passages la. and lb, causes cooling of the adjacent parts which dissipates heat generated-by the rapid expansion and contraction of the rubber` cushion members l and 8.` It will be here noted that during r ciprocation of the piston hammer 3, that air must ebb and flow freely fromY the bore laof the cylinder l, at the hammer end 3a.

ofA thefront head 2 of my clay digger in thev earth.

Though, I have shown and described a particular construction, combination and arrangement of parts and portions, I do not wish to be limited to the particular construction, combination and arrangement, but desire to include in the scope of my invention, the construction, combination and arrangement substantially as set forth in the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a clay digger of the class described, the combination cfa cylinder, a piston hammer reciprocally. mounted therein, said cylinder havingfabore portion at the hammer end of said piston hammer provided with a breather opening therein, said cylinder provided with an exhaust. port arranged to be passed by the opposite end of said piston hammer, and a pair of passages having their open ends in spaced relation to each other, hollow passage means com. municating with the breather opening in the side wall of the bore .portionat the hammer end of said piston hammer, said pair of hollow passages terminatingnear said exhaust port of said 'cylinder whereby exhaust from said cylinder exhaust port adapted to be passedby one end.

of said piston, the opposite end of said pistonprcvided with a hammer portion, said cylinder provided withy a bore portion at` said hammer portion'of said piston, and passage means having a pair of hollow passages therein and having spaced open ends extending from. the inn terior of said bore portion at the hammer end of said piston to a position nearY said exhaust opening of said cylinder whereby exhaust from saidcylinder emerges adjacent the open ends of said hollow passages, entering, one of said passages and cy-passing the open end of the other passage in spaced relation thereto, one of said hollow passages terminating near said exhaust port and the other hollow passage in stepped re lation therewith slightly spaced from said ex-Y haust port.

3. In a clay digger of the class described, the combination of a substantially conventional pneumatic hammer cylinder, a piston hammer reciprocally mounted therein having a hammer portion at one end thereof, said cylinder provided with an exhaustV port in the side wall thereof arranged to be' passed by the opposite end-of said piston hammer from said hammer portion, said cylinder provided with a bore portion lnear the hammer portion of said piston hammer, and hollow passage means having a pair of passages therein having spaced open ends at different distances from said exhaust port communicating with said bore portion at the hammer portion of said piston hammer and terminating near said exhaust port of said cylinder whereby exhaust from said cylinderremergesadjacent the open ends ofsaidr hollowfpassages, entering one of said passages andbyfpassing the open end of the adjacent passage spacedthereto.

4.v In a clay digger of the class described, the combination of a substantially. conventional.

pneumatic hammer cylindeiga pistonhammer;A

reciprocally mounted therein having a hammer portion' at one end thereof, said cylinder provided with an exhaust port in the side wall thereof arranged to be passed by the opposite end of said piston hammer from said hammer portion, said cylinder provided with a bore portion near the hammer portion of said piston hammer, and hollow passage means having a pair ofpassages therein having spaced open ends at different distances from said exhaust port communicating with said bore portion at the hammer portion of said piston hammer and terminating near said exhaust port of said cylinder whereby exhaust from said cylinder emerges ad jacent the open ends of said hollow passages, entering one of said passages and lay-passing the open'end of the adjacent passage spaced thereto, said exhaust port directed outwardly and forwardly toward the open ends of said hollow passage portions.

5. In a clay digger of the class described, the combination of a substantially conventional pneumatic hammer cylinder, a piston hammer reciprocally mounted therein having a hammer portion at one end thereof, said cylinder provided with an exhaust port in the side wall thereof arranged to be passed by the opposite end of said piston hammer from said hammer portion, said cylinder provided with a bore portion near the hammer portion of said piston hammer, and hollow passage means having a pair of passages therein having spaced open ends at different distances from said exhaust port REFERENCES CITED The following references are"of record in the file of this patent:

UNITED STATES PA'IENTS Number Name Date 835,290 Richwood Nov. 6, 1906 $871,756 Graham Nov. 19, 1907 1,084,152 Kessel Jan. 13, 1914 1,109,782 Purcell Sept. 8, 1914 1,223,027 Brackett Apr. 17, 1917 1,641,357 Slater Sept. 6, 1927 1,889,422 Shook Nov. 29, 1932 2,019,332 Atkins Oct. 29, 1935 2,102,576 Skaer Dec. 14, 1937 2,201,485 Forss May 21, 1940 

